Fertility control Flashcards
Progestogen as a drug
A contraceptive that works by:
- Preventing ovulation by inhibiting LH surge
- Thickening cervical mucus: inhibits sperm movement
- Thins the endometrium: does not support fertilised ovary [hostile endometrium]
When used alone as a contraceptive= 8 per 100 pregnancy
Oestrogens as a drug
A contraceptive that works by:
- Suppressing FSH levels: prevents the development of the follicle
When used combined with progestogen= 3 per 10,000 pregnancy/ year
- In brighton = 5 per 100
Combined oral contraceptive administration
Day once daily for 21 days
- Then 7 days drug free [not necessary]
Free drug day allows withdrawal bleed
- Confirms pregnancy
- Reduces risk of endometrial cancer [due to thickening]
Missing the pill at the start or the end of the month increases the chance of pregnancy
- Increases drug free day allowing time for development of follicle
Contraindications of oral contraceptives
Taking antibiotics
- Gut bacterial metabolises contraceptives
Having diarrhoea/ vomiting
- Pill not absorbed.
Progesterone-only contraceptive
- Examples
- Mechanism
- Adverse effect
Progestogens:
- Norethisterone
- Desogestrel
- Levonorgestrel
Mechanism
- Prevents LH surge= inhibits ovulation
Adverse effects
Vaginal contraceptives
Delivery of hormones vaginally
- Ring secretes the hormones for 21 days then taken out.
- Left for 3 hours then put back in
Implant contraceptive
Inserted into the skin and release progestogen for 3 years
- No drug free days
Intrauterine contraceptives
IUD=Plastic rod, most effective contraceptive
- Causes local sterile inflammatory response = prevents implantation of fertilised ovum.
IUS- secretes progestogen
Emergency ‘morning after’ contraception
Levo-norgestrel [progestogen]
- Taken for 2 days
- Blocks LH surge but will not prevent abortion as cannot stop fertilisation [if occurred in window]
- Prevents implantation of fertilised ovum
Ulipristal [partial agonist of progesterone receptor]
- More effective than levonorgestrel
- Prevents thickening of endometrium
Induced abortion
Mifepristone
- Progesterone antagonist
Induces abortion by inhibiting the support of fertilised ovum
Male oral contraceptives
- Testosterone
Sperm takes 3 months to develop
Administering testosterone caused inhibition of endogenous testosterone
- Loss of male pattern pubic hair
- Muscle development
- Loss of libido
- Regression of genitalia
Male oral contraceptives
- Testosterone and progestogen
Progestogen= inhibition of testosterone production
Testosterone given to replace loss of endogenous androgens.
- Every 8 weeks
